Liquid crystals are fluids characterized by various forms of long-range molecular order. These materials have found extensive uses in switchable electro-optical devices, such as liquid crystal displays and spatial light modulators. For many photonic applications it is desirable to have materials capable of freezing liquid crystalline order into solid state without crystallization, representing a unique class of advanced materials referred to as glassy liquid crystals, (GLCs). Existing GLCs can be categorized as follows:                laterally or terminally branched, one-string compounds with a glass transition temperature, Tg, mostly around room temperature [cf. Sorai, M.; Seki, S. Bull. Chem. Soc. Jap. 1971, 44, 2887; Tsuji, K.; Sorai, M.; Seki, S. Bull. Chem. Soc. Jap. 1971, 44, 1452; Wedler, W.; Demus, D.; Zaschke, H.; Mohr, K.; Schafer, W.; Weissflog, W. J Mater. Chem. 1991, 1, 347.];        twin molecules with an above-ambient Tg but generally lacking morphological stability [cf. Attard, G. S.; Imrie, C. T. Liq. Cryst. 1992, 11, 785; Dehne, H.; Roger, A.; Demus, D.; Diele, S.; Kresse, H.; Pelzl, G.; Weissflog, W. Liq. Cryst. 1989, 6, 47; Attard, G. S.; Imrie, C. T.; Karasz, F. E. Chem. Mater. 1992, 4, 1246; Tamaoki, N.; Kruk, G.; Matsuda, H. J. Mater. Chem. 1999, 9, 2381]; cyclosiloxanes functionalized with mesogenic and chiral pendants [cf. Kreuzer, F. H.; Andrejewski, D.; Haas, W.; Haberle, N.; Riepl, G.; Spes, P. Mol. Cryst. Liq. Cryst., 1991, 199, 345; Kreuzer, F. H.; Maurer, R.; Spes, P. Makromol. Chem., Macromol. Symp. 1991, 50, 215; Gresham, K. D.; McHugh, C. M.; Bunning, T. J.; Crane, R. J.; Klei, H. E.; Samulski, E. T. J Polymer Sci.: Part A: Polymer Chem. 1994, 32, 2039];        carbosilane dendrimers exhibiting a low Tg[cf. Lorenz, K.; Hölter, D.; Stühn, B.; Mulhaupt, R.; Frey, H. Adv. Mater. 1996, 8, 414; Ponomarenko, S. A. Boiko, N. I.; Shibaev, V. P.; Richardson, R. M.; Whitehouse, I. J.; Rebrov, E. A.; Muzafarov, A. M. Macromolecules 2000, 33, 5549; Saez, I. M.; Goodby, J. W.; Richardson, R. M. Chem. Eur. J. 2001, 7, 2758]; and        Macrocarbocycles with mesogenic segments as part of the ring structure [cf. Percec, V.; Kawasumi, M.; Rinaldi, P. L.; Litman, V. E. Macromolecules 1992, 25, 3851].        
A series of recent papers reported a new molecular design concept, in which nematic and chiral groups are chemically bonded to a volume-excluding core to prevent crystallization upon cooling [cf. Shi, H.; Chen, S. H. Liq. Cryst. 1994, 17, 413, Liq. Cryst. 1995, 18, 733, Liq. Cryst. 1995, 19, 785, and Liq. Cryst. 1995, 19, 849; Mastrangelo, J. C., Blanton, T. N.; Chen, S. H., Appl. Phys. Lett. 1995, 66, 2212; Chen, S. H.; Mastrangelo, J. C.; Shi, H.; Bashir-Hashemi, A.; Li, J.; Gelber, N., Macromolecules 1995, 28, 7775; De Rosa, M. E.; Adams, W. W.; Bunning, T. J.; Shi, H.; Chen, S. H. Macromolecules 1996, 29, 5650; Chen, S. H., Mastrangelo, J. C.; Blanton, T. N.; Bashir-Hashemi, A. Liq. Cryst. 1996, 21, 683; Chen, S. H.; Shi, H.; Conger, B. M.; Mastrangelo, J. C.; Tsutsui, T. Adv. Mater. 1996, 8, 998; Chen, S. H.; Mastrangelo, J. C.; Blanton, T. N.; Bashir-Hashemi, A. Macromolecules 1997, 30, 93; Chen, S. H.; Katsis, D.; Mastrangelo, J. C.; Schmid, A. W.; Tsutsui, T.; Blanton, T. N. Nature 1999, 397, 506].
As a result, the long-range order characteristic of liquid crystal fluids are preserved in glassy state with superior stability against thermally activated recrystallization. Glassy nematics with the highest phase transition temperatures and the broadest mesomorphic fluid temperature range ever reported have been achieved [cf. Fan, F. Y.; Culligan, S. W.; Mastrangelo, J. C.; Katsis, D.; Chen, S. H.; Blanton, T. N. Chem. Mater. 2001, 13, 4584; Fan, F. Y.; Mastrangelo, J. C.; Katsis, D.; Chen, S. H.; Blanton, T. N. Liq. Cryst. 2000, 27, 1239].
Of all the GLCs, chiral nematics are of particular interest because of the potential for use as large area nonabsorbing polarizers [cf. Katsis, D.; Chen, H. P.; Mastrangelo, J. C.; Chen, S. H.; Blanton, T. N. Chem. Mater. 1999, 11, 1590], optical notch filters and reflectors [cf. Chen, H. P.; Katsis, D.; Mastrangelo, J. C.; Chen, S. H.; Jacobs, S. D.; Hood, P. J. Adv. Mater. 2000, 12, 1283], and polarized fluorescent films [cf. Chen, S. H.; Katsis, D.; Mastrangelo, J. C.; Schmid, A. W.; Tsutsui, T.; Blanton, T. N. Nature 1999, 397, 506]. This class of materials has been synthesized by a statistical approach [cf. Chen, S. H.; Mastrangelo, J. C.; Blanton, T. N.; Bashir-Hashemi, A. Liq. Cryst. 1996, 21, 683; Katsis, D.; Chen, H. P.; Mastrangelo, J. C.; Chen, S. H.; Blanton, T. N. Chem. Mater. 1999, 11, 1590], which requires intensive work-up procedures to arrive at pure components, and by a deterministic approach via 2,4-dioxo-3-oxa-bicyclo[3.3.1]nonane-7-carboxylic acid chloride as an unstable intermediate prepared under demanding conditions [cf. Shi, H.; Chen, S. H. Liq. Cryst. 1995, 19, 849; Chen, H. P.; Katsis, D.; Mastrangelo, J. C.; Chen, S. H.; Jacobs, S. D.; Hood, P. J. Adv. Mater. 2000, 12, 1283].